You should try with io_devctl() function. Search for "DCMD_FSYS_STATISTICS" in QNX help.Beware that QNX documentation states that : "There is no supported utility which obtains this, the fs_stats is completely undocumented, and may/will change in the future, and certainly has changed in the past."

Just realised that io_devctl() is not what you need. I've been too fast analysing the search result.io_devctl() function is for managing devctl() calls to a resource manager you write. Definitively not what you need.Sorry for this mistake.